Remaining Time increases

Altair Forum User

Hi, 

 

I am currently trying to simulate quite a simple impact on a wall of several pieces. 

I have no intersections and no penetrations, the run model checker is all green but when I start the calculation, the remaining time decreases for a little time and then increases with no apparent reason.

 

Do you have an idea of the origin of my problem ?

 

Best regards,

Guillaume

Altair Forum User

Hi  Guillaume,

This can due to the time step frop in the model. Please review the engine out (_0001.out) file so that you can review the time step and what is causing the tie step to drop.

It can be due to an element, a node or an interface.

•For an element, check the related material (especially its Young modulus and density in case of an elastic-plastic material; and its viscosity in case of a visco-elastic material). There must not be an error in the units system that this data is given in.

Check the size of the element, since elemental length is proportional to time step.

•For a node, check the characteristics of connected elements. If the node is on the master side or the slave side of an interface, this interface must be verified.

•For an interface, the gap of the interface must be verified if some failure happens on the master or the slave side of the interface.

Once this is cleared you can run the simulation without time step being dropped.

Else you can try with imposing time step in the model. You can watch this webinar http://www.altairuniversity.com/learning-library/considerations-about-time-step/ which describes the same

 

<?xml version="1.0" encoding="UTF-8"?>